AN2267 Datasheet, PDF (1/19 Pages) STMicroelectronics – Implementation of current regulator for BLDC motor control with ST7FMC

AN2267
Application note
Implementation of current regulator for BLDC
motor control with ST7FMC
Introduction
A conventional method of controlling BLDC motors is to implement an inner current loop for
torque / current control. Reference to this inner loop is provided either by an outer speed
loop or by some other means based on application requirement. The linearity of inner
current / torque loop is greatly affected by the faithfulness of current feedback. In the first
section, an outline to various approaches for obtaining current feedback is presented and
analyzed with the limitations of each. In the subsequent sections, a presentation is given of
a simple, linear and cost effective approach of implementing the inner current loop by
sampling the DC link current at the mid-point of PWM “on time” with ST7FMC. Experimental
results are also discussed.
An accompanying software file is available with this application note and can be downloaded
from www.st.com/mcu
June 2006
Rev 1
www.st.com
1/19